The record remains. Michael Whitaker of Britain easily rode Henderson Didi over the 7-foot-3 wall to win the $15,000 Puissance at the Washington International Horse Show at Capital Centre last night. The record of 7-7 1/2 set here in 1983 by Anthony D'Ambrosio of Mount Kisco, N.Y., and Sweet N' Low, was untouched.

Margie Goldstein and Daydream, winners in the event last year at 7-2, were second.

Just 10 entries competed in the event, about one-third the number entered in most international open jumper classes during the week.

The Puissance is particularly difficult and strenuous for the horse. The course consists of three fences and "the wall." After all competitors finished a round, wooden bricks were added to raise the height of the wall, which started at 6-2.

Eight competitors cleared that height to advance to a second round. Four cleared at 6-8. Only Goldstein and Whitaker cleared the 7-foot mark to continue.

Daydream refused a first attempt at 7-3, scoring three faults, before clearing the height. Whitaker and Henderson Didi easily cleared that height, but declined to try for the record.

Whitaker, the top rated rider in the world, has ridden the 10-year-old Belgian-bred horse to three other Puissance victories recently, and 20 in his career. Last month they won in England at 7-2 and in Germany at 7-5. Two weeks ago the horse and rider again made the 7-5 jump for a victory. The Puissance is a much more common event in Europe, where almost every horse show has such a class, and many riders have horses specifically for it.

Joe Turi of Britain rode cleared the wall at 7 feet, but a moment's hesitation before the stretch to the wall was penalized with three faults for third place.

Britain took first place in the show's team standings, with 36.5 points. France, which did not compete, has 34; the U.S. national team has 29.5 and Canada 9.

Whitaker's victory moved him into first place in the standings for leading individual rider and leading international rider. He leads Debany, 12-11, in the overall competition and the international division (limited to members of national teams). Todd Minikus of Lake Forest, Ill., has a a four-point edge in the "national" (or unattached) rider competition.

Earlier, Kelly Robinson of Monte Sereno, Calif., and her mount Count On Me had the fastest clean jumpoff round in the Senator's Cup Junior Jumper Stake, winning in 30.173 seconds. The victory gave Count On Me the grand champion title in the jumior jumper division with 10 points.

Carone, ridden by Lauren Hough of Morgan Hill, Calif., was runner-up (30.332) and had the other clean jumpoff round. Zoef, ridden by Carrie Ellington of Lebanon, N.J., was third with four faults in 29.247 seconds. Zoef won the event here last year.

Eleven of 28 competitors finished the first round without fault to advance to the jumpoff.

Grandessa, ridden by Darren Graziano of Warren, N.J., had enough points from all junior jumper events this week to tie for reserve champion honors with five points. Reebok, and rider Kim Sweeney of Hockley, Tex., were also awarded reserve champion status with five points.

Splish Splash, owned and ridden by Elisabeth Strunck of Davidsonville, Md., was named champion with 15.2 points in the local pony finals. The horse won a year ago, when Strunck's sister, Louise, rode in the event.

Woodlands Cloudy Candy, ridden and owned by Tolley Ewing of Monkton, Md., tied for reserve honors with All In Favor and rider/owner Jocely Piccinetti of Columbia, Md., with nine points each.

Rain Goose, owned and ridden by Margaret Stewart of the District, was next with 8.1 points.

RESULTS

$15,000 International Open Jumper Puissance: (horse, rider, height) 1, Henderson Didi, Michael Whitaker, 7-3; 2, Daydream, Margie Goldstein, 7-3, 3 faults; 3, Ever If Ever, Joe Turi, 7-0, 3 faults; 4, Elan's 2 + 2, 6-8; 5, (three-way tie): Crosby, Nigel Coupe, 6-8, 4 faults, Tarco, Alice Debany and Clover Mountain, Todd Minikus.

Green Conformation Hunter: (horse, owner) Grand Champion: Conversation Piece, Shelly Stiegler; Reserve: Paris Lights, Sheila & Michael Ashkin.

Regular Conformation Hunter: Grand Champion: Bib and Tucker, Lisa Inganamort; Reserve: Meant To Be, Leann Morris and Don Stewart Jr.

Amateur/Owner Under 30: Grand Champion: Gaelic Cross, Sloan Lindemann; Reserve: Cover Girl, Andrea Schultz.

Amateur/Owner 31 and over: Grand Champion: Benjamin, Anne Hall; Reserve: Incentive, Sally Smith. Amateur/Owner Jumper: Grand Champion: Kid Gloves, Denise Cojuangco; Reserve: Hearsay, Kate Chope.